Portable lighting devices, such as lighting devices that are to be worn, are well known in the art. In many cases, a user may place a light on their head proximate their face. The light is then directed toward objects in the immediate vicinity of the user. As an example, these types of headlights may be used in surgical procedures. Medical and dental professionals often use surgical headlights to provide additional illumination of a surgical site on a patient. Surgical headlights may be attached to glasses or loupes to be worn by the clinician.
Existing headlights can be deficient in one or more aspects. For one, they may exhibit poor light uniformity and/or unacceptable color separation at the edge of the light beam. In addition, surgical headlights may be too heavy or awkward and are therefore uncomfortable. As such, clinicians consider size, weight, and ease of adjustment when selecting a headlight for use in surgical procedures.
To address some of these problems, U.S. Pat. No. 8,047,684 seeks to provide a more uniform light beam by positioning a singlet lens between a light-emitting diode (LED) and a doublet lens. This arrangement however has a drawback and does not address many of the clinicians' selection criteria. For example, the positioning of the doublet lens at the distal opening of the housing results in the doublet lens having a relatively large diameter, and thus the doublet lens is relatively heavy. During lengthy surgical procedures, the clinician may experience head and neck discomfort and/or pain because of the relatively heavy doublet lens.
Therefore, a need exists for a headlight which provides a more uniform light beam, and which is both lightweight and comfortable.